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mars opposition- by John Hlynialuk, Bluewater Astronomical Society

You have probably noticed a bright orange star rising in the southeast around 10 pm recently. Readers of this column are probably not fooled by appearances and recognize a planet when they see one. In fact, this is Mars, amateur astronomers' main telescopic attraction of 2018. This summer will be the best time to view Mars since its record 2003 appearance, the one that started the internet Mars Hoax. Let me fill you in on this year's spectacular Mars appearance before sorting out the "fake Mars news" that you may have already encountered online.

Earth and Mars circle the Sun at different rates. Earth takes 365.26 days and Mars takes 688.41 days or 1.8847 Earth years to complete its orbit. So approximately every two years we catch up to Mars and both planets are on the same side of the Sun (opposition) and right beside each other in the solar system. Since planet orbits are actually ellipses, there is a small variation from year to year in the actual separation, -every 15 to 17 years we get a particularly close approach. In 2018, the separation is only 2 million km farther than in August 2003, a once-in-60 000-year event. To the naked eye, the only difference at opposition is that Mars appears as a brighter star-like object in our sky. The view is much more spectacular in a telescope because on the planet's visible disk are surface features like polar caps, dusky markings and wispy clouds. And though closest approach is on a specific date, July 27, Mars viewing remains excellent for several months and, in fact, is better after opposition since Mars is already visible in the evening sky when it gets dark. If, for some reason, you miss this one, at the next opposition in 2020, Mars will be only slightly smaller in telescopes (still good viewing) and a touch less bright to the naked eye. After that Mars shrinks in apparent size more noticeably and will not get back to the 2018 size until Sep 2035.

As for the Mars Hoax, the whole "Mars will be as big as the full Moon" meme started with a legitimate Griffiths Observatory press release at the 2003 Mars opposition. It said something like: "At a modest 75-power magnification Mars will look as large as the full moon to the naked eye". Note that the comparison involves a telescopic view of Mars and a naked eye view of the Moon. Some unknown reporter (with little astronomical common sense) altered this by leaving out any mention of the 75-power telescope magnification of the planet! After that, fake graphics also appeared showing a Hubble Space Telescope image of Mars pasted next to a full Moon image, both the same size. So as the result of definitely sloppy editing and a bit of Photoshop "magic" the Mars Hoax was born.

The Mars Hoax appears to drop down from its home in cyber-space whenever "August" and "Mars" show up in the same sentence online, even during years when Mars is in the daytime sky near the Sun like it was in July 2017 (again in September 2019). At those times when it is not even visible, many get random reminders to "take your kids out for the once-in-a-lifetime event -Mars as big as the full Moon!" Sorry folks, it is fake (and really old) news.

For this year's Mars observations, however, there is one problem. It started out small and grew to planet-sized proportions. A month ago, a dust storm was observed on the planet

and it has now effectively shrouded the entire globe of Mars in a pale "pumpkin-orange" cloud of hazy dust. Views through our telescopes have been pretty nondescript, -not even the polar caps are visible. Overall, the dust cloud has actually made the entire planet appear slightly brighter to the naked eye, but that is not much consolation to amateur astronomers. There is glimmer of hope in the gloom, however, since there are signs that the storm has peaked and may be subsiding. We are hopeful that Mars viewing will get better late in the summer and early fall. Look for my regular updates on the situation in my weblog on our club website.

Meanwhile, keep your fingers crossed for clear skies, both here and on Mars. For viewing dates this summer at the Fox Observatory, please check our website www.bluewaterastronomy.com and the up-to-date information about Mars in my weblog under the WEBLOG tab.

Clear skies!

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